Photocatalytic detoxification of a sulfur mustard simulant by donor-enhanced porphyrin-based Covalent-Organic Frameworks

Abstract

Photocatalytic detoxification of sulfur mustards (e.g., bis (2-chloroethyl) sulfide, SM) is an effective approach to protect the ecological environment and human health. In order to fabricate COFs with high performance for the selective transformation of SM simulant 2-chloroethyl ethyl sulfide (CEES) to nontoxic 2-chloroethyl ethyl sulfoxide (CEESO), three porphyrin-based COFs with different donor groups (R=H, OH, OMe) were synthesized. Among these COFs, COF-OMe, which possesses the strongest electron-donating ability, demonstrated a faster and higher detoxification rate of CEES at various concentrations, achieving selective oxidation of CEES to non-toxic CEESO with 99.2% conversion and 100% selectivity using white LED light irradiation within three hours. The facilitated charge transfer and separation as well as efficaciously produced reactive oxygen species (ROS) including singlet oxygen (1O2) and superoxide radical anions (O2•−) are supposed to contribute to the excellent performance. The results demonstrated that the donor-enhanced porphyrin-based COFs could act as heterogeneous photocatalysts for visible light driven organics transformation and detoxification of sulfur mustards.